Silk screen printing



Sept. 11, 1962 c. D. BLACK 3,053,374

SILK SCREEN PRINTING Filed April 8, 1960 5 Sheets-Sheet 1 M I U W Q MW PifiI ENToR. C/m'enae 25/406 Sept. 11, 1962 c. D. BLACK 3,053,374

SILK SCREEN PRINTING Filed April 8, 1960 I 5 Sheets-Sheet 2 INVENTOR. flare/me 0, 5/406 Sept. 11, 1962 c. D. BLACK SILK SCREEN PRINTING 5 sheets sheet 3 Filed April 8, 1960 INVENTOR.

B/ak 4 TTOENEK illlllllrllllbln United States Patent 3,053,374 SILK SCREEN PRINTING Clarence D. Black, Kansas City, Mo, assignor to Ionsolidated Thermoplastics Company, Stamford, @onn, a corporation of Delaware Filed Apr. 8, 1960, Ser. No. 20,879 14 Claims. Cl. 19824) This invention relates to machines for silk screen printing of plastic containers and refers more particularly to such machines for printing both sides of such plastic containers.

This application is a continuation-in-part of my application Serial No. 573,908, filed March 26, 1956, for Silk Screen Printing Apparatus Improvement.

Previously, machines have been provided for the silk screen printing of one surface of oval, molded or blowmolded bottles of plastic material such as polyethylene. A conventional machine includes a base frame and a screen rack of rectangular shape mounted relative to said frame, said rack having a silk screen mounted in the floor thereof, the screen adapted to receive printing ink thereon. A resilient swab of rubber or the like is positioned on said frame relative to said screen rack and screen. Means are provided for moving the swab vertically up and down relative the rack into and out of contact with the silk screen. Means are also provided for moving the rack horizontally from a starting position relative to said swab whereby to periodically force ink through the screen in a printing step and to coordinate and time the motions of the rack and swab relative to one another so the swab is down in said printing step to contact the screen and up away from the screen for a recovery step wherein the rack returns to its original starting position.

Means additionally must he provided to position a container relative to the silk screen and, as the screen moves across with the rack under the swab in the printing step, move the oval container in an are along with the motion of the screen to receive on successive areas of the container the ink forced through the screen by the swab. Previously, such container positioning means have comprised only a single orificed clip adaptable to receive a single container which (1) is charged by hand in a pause on one side of the screen, (2) swings across a limited arc in the printing step, (3) pauses on the other side of the screen after the printing step where the container is removed by hand, (4) returns uncharged with the rack and screen in a recovery step and (5) is charged again, etc. Such a manipulation of the containers to be printed in the screening process is slow, inaccurate, requires excessive human action in a small area, does not utilize the full capacity of the machinery, is prone to permit errors of the operator which result in smearing of the ink on the printed container and, finally, is highly boring to the operator. Additionally, for safety sake, the pauses for charging and removal either must be made sufficiently long to allow for the operators cumulative fatigue if automatic, or governed by the operator by foot operated release equipment or the like. High rates of production in such known conventional devices are thus impossible.

In my application Serial No. 573,908, supra, I disclosed a silk screen printing apparatus improvement which provided for automatic insertion of the oval containers in a magazine, rotation of the magazine through a silk screen printing step, and automatic ejection of the conice tainer from the magazine onto a drying apparatus. In this apparatus, an unprinted container was charged to one magazine cavity simultaneously with the discharge of a printed container from another cavity of the same magazine. This simultaneous charging and discharging step alternated with a magazine rotation step which coincided with the actual screening of the single side of the container. Shortcomings of even this machine have been identified in that neither the conventional apparatus nor my previous apparatus will print both sides of the container in one charging to the machine. Additionally, if the containers are recycled to the machine after drying for silk screen printing of the other side thereof, there are the problems of damage to or destruction of the printing on the already printed side and requirement of careful orientation in insertion by the operator so the other blank side will be printed.

Therefore, an object of the present invention is to provide a silk screen printing apparatus which prints containers on both sides thereof by a silk screen printing process in a single charging of a container to the apparatus.

Another object of the invention is to provide silk screen printing apparatus which prints both sides of a container without any threat or damage to either side of the container and requires no operator handling of the container after the initial charge thereof to the apparatus.

Another object of the invention is to provide a silk screen printing apparatus for printing both sides of a container on a single charge of the container to the machine, wherein means are provided to entirely automatically transfer a container to be printed successively into and out of two rotatable magazines and thereafter onto a drying mechanism and without any threat to the integrity of the printing on either side of the container itself.

Another object of the invention is to provide a silk screen printing apparatus for oval plastic containers to print both sides thereof, which apparatus is exceedingly simple in view of the complex task to be accomplished, is extremely rugged over long periods of high speed operation, is relatively cheap and inexpensive to manufacture, and wherein all of the parts are readily accessible for replacement, inspection or repair.

Another object of the invention is to provide apparatus for printing both sides of a plastic container which greatly speeds up the printing process and enables the printing of both sides of the container without an intermediate drying step and without requiring double handling of the container by the machine operator.

Another object of the invention is to provide a silk screen apparatus adapted to print both sides of a container upon a single charge thereof to the machine, the entire apparatus having only two stages, successively applied, a simultaneous feed, transfer and discharge stage and a printing stage, whereby all feed, transfer and discharge operations of containers in the apparatus are simultaneously accomplished, and both printing stages are simultaneously accomplished.

Another object of the invention is to provide a silk screen printing apparatus adapted to print both sides of a container, wherein opposite sides of two different containers are simultaneously silk screened, whereby to permit simultaneous actuation of both silk screen squeegees and, also, simultaneous translation of both silk screen frames and racks.

Other and further objects of the invention will appear in the course of the following description thereof.

In the drawings, which form a part of the instant specification and are to be read in conjunction therewith, an embodiment of the invention is shown and, in the various views, like numerals are employed to indicate like parts.

FIG. 1 is a plan view of the inventive apparatus for silk screening both sides of a container with the silk screen frames removed therefrom to better show the basic operating apparatus thereunder.

FIG. 2 is an end view of the apparatus of FIG. 1 from the right-hand side of FIG. 1, a silk screen frame removed to better illustrate the relationships of the parts.

FIG. 3 is a plan view, similar to that of FIG. 1 but enlarged, and partial, the silk screen frames in position, with cross arm construction thereabove not seen, the view taken roughly along the line 33 of FIG. 2 in the direction of the arrows.

FIGS. 4, and 6 show in plan view various stages of the printing of both sides of a single container in the inventive apparatus.

FIG. 4 illustrates, in plan view, the insertion of a container to be printed in the feed guide before feeding (full lines) and the feeding of said container into a first magazine cavity (dotted lines).

FIG. 5 is a view subsequent to the view in plan of FIG. 4 with the first magazine having rotated in a first silk screen printing stage in the direction of the arrow prior to feeding the already one side printed container into a second magazine cavity (full lines), and feeding said printed container into the second magazine cavity prior to printing the other side thereof (dotted lines).

FIG. 6 is a view in plan subsequent to that of FIG. 5 wherein the second magazine has rotated in the direction of the arrow through a second silk screen printing stage to position the container, then printed on both sides, for discharge from the second magazine (full lines), and discharging the container therefrom to receiving means (dotted lines).

FIG. 7 is an end view subsequent to FIG. 4 of a portion of the inventive apparatus showing the printing step of the first container side wherein the first magazine is rotated as in FIG. 5 relative to a silk screen and ink is applied therethrough by motion of the screen relative to a squeegee.

FIG. 8 is an end view of the second printing magazine as in FIG. 6 wherein, during rotation of the second magazine as in FIG. 6, the other side of the said container is printed in a second silk screen operation with a second squeegee wiping printing ink through a second silk screen against the container surface as the screen is moved relative the squeegee in concert with the rotation of the magazine.

FIG. 9 is a cross-sectional view along line 9-9 of FIG. 6 in the direction of the arrows.

Referring to the drawings, all of the apparatus parts of the subject silk screening device are mounted on a base frame including a table surface 20, upwardly extending support arms 21 and 22 at the sides of the table and suitable downwardly extending legs (not shown). Upper and lower cross bars 23 and 24 extend between arms 21 and 22 and are adjustable relative thereto for vertical movement to selected fixed vertical positions by suitable mechanism. Elongate plates or guides 25 are slidably mounted on cross bar 24 by suspension and bearing means 26 interconnecting plates 25. Stop means 27 are adjustably positioned on top of cross bar 24 to limit the to and fro motion of plates 25 on bar 24. Pneumatic cylinder 28 is fixed to the left-hand support arm in FIGS. 2 and 3 and has the extendible piston rod 29 thereof connected rigidly to crosstie means (not shown) fixed to the lower portions of plates 25 below cross bar 24, said means not shown. Conventional rectangular silk screen racks 30 and 31 are removably connected to the outer faces of plates 25 and have suitable silk screens 32 and 33 positioned therein. Back and forth motion of plates 25 actuated by hydraulic cylinder 28 carries the silk screen racks and 31 horizontally back and forth simultaneously therewith. Fixed to the outer edges of upper plate 25 in the view of FIG. 3 are arms 34 and 35 extending in horizontal orientation and having cable 36 interconnecting the upper ends thereof in FIG. 3 in a manner and for a purpose to be described.

Fixed to cross bar 23 are paired hydraulic cylinders 37 and 38 (FIG. 2) having input and output hydraulic connections of conventional type thereto in the manner of cylinder 28. These cylinders simultaneously alternatively thrust downwardly and retract elongate shafts 39 and 40 to which are attached conventional squeegees 41 and 42. Suitable masses of printing ink and ink blocks (not shown) are positioned during operation on the silk screens 32 and 33, the latter to control the position of the printing ink masses on the silk screens relative to the squeegees whereby to permit the periodical forcing of ink through the configured silk screens to print containers. In the operation of the system shown, the squeegees are forced down to print as frames 30 and 31 move from left to right in FIGS. 2 and 3 and are pulled up to permit free reverse motion of frames 30 and 31 to retract the frames in preparation for a second printing step.

The apparatus previously described is substantially identical as to structure and function (save for the addition to the frame of an extra silk screen frame and squeegee) to that shown in my prior application Serial No. 573,908, supra, of which the instant application is a continuation-in-part.

Particularly referring to FIGS. 1, 4, 5 and 7, a first shaft 43 is rotatably mounted in bearing blocks 44 and 45' on a platform 46 supported by a plurality of means 47 above the surface of table 20. Fixed to one end of shaft 43 is first magazine 48 (see FIG. 7) having a pair of cavities 49 formed in the outside surface thereof 180 opposed from one another. Cavities 49 have open outer sides to permit the exposure of one side of a container to be printed as may be seen in FIG. 7. The depth of the cavities is slightly less than the thickness of the containers to be printed. The width of the cavities 49 is slightly less than the width of the containers whereby to frictionally engage and retain the same. The cavities 49 are relieved internally thereof as at 50 to avoid abrasion, etc. of the side of the container which is not to be printed in magazine 48.

Fixedly attached to the other end of shaft 43 is ratchet disc 51 having a multi-station ratchet of conventional type thereon, cooperating with drive drum 52 which only permits rotation of shaft 43 in a single direction (clockwise in FIG. 2 or left to right viewing FIG. 1 from the orientation of the figure designations in the drawings). The other operating portion of the conventional ratchet, the pivotal pawl, is mounted on the adjacent face of drum 52, rotatably and freely mounted on shaft 43. The ratchet details are identical to those of Serial No. 573,- 908, supra. Drum 52 also received by encirclement cable 36, whereby reciprocation in a horizontal direction (left to right in FIG. 3) of plates 25 also rotates shaft 43 in the said one direction by the frictional engagement of cable 36 with drum 52. The shaft 43 drives described also is the same as that of my application Serial No. 573,908, supra.

Bearing 53 aids in rotatably supporting the outer end of shaft 43 and nylon brake disc 54 is fixed to the outer end of shaft 43 and is frictionally engaged by a conventional friction brake ring shown at 55 to avoid overshooting of shaft 43 and magazine 48 in positive rotation and assure action of the ratchet mechanism to avoid rotation of shaft 4-3 in the opposite direction under impetus of cable 36.

Second magazine 56 (see FIG. 8) is rotatably mounted on shaft 59, the latter supported on plate 46 by bearing block 60 A chain 61 engages spur gears (not shown) on shafts 43 and 59, to provide simultaneous rotation of the two shafts in the single previously-mentioned direction and also the magazines mounted thereon. Both magazines are simultaneously driven an equal rotational distance (180") for each full reciprocation of the screen frames 30 and 31 in a printing cycle and return. The parts of magazine 56 which are identical to magazine 48 are numbered the same, but primed.

A first slide guide 62 is fixedly mounted on plate 46 by suitable means whereby to horizontally extend between opposed sides or faces of magazines 48 and 56 in the manner shown in FIG. 1. The ends of slide guide 62 are as closely positioned to the opposed magazine faces as possible so that containers may be transferred into and out of the slide guide from and to the respective magazines without required human handling. The structure of slide guide 62 in cross section is identical with that construction shown of second slide guide 63 positioned parallel thereto as seen in FIG. 9, but the open sides are faced in diflerent directions. Thus the structure of FIG. 9 only will be described. Slide 63 has an open side face 64 along the entire length thereof of sufficient width to both engage the container against fallout thereof and also to avoid contact with any printing on the side thereof. A relieved groove 65 along the inside face thereof avoids contact with printing on the other side of the container. Any container passing through slide guide 63 has both sides printed. All subsequent discussion of FIGS. 1 and 49 regards them as if the figure designations were toward the reader. Any container passing through slide guide 62 has only one side thereof printed, the side to the right in FIG. 1 (toward slide guide 63 and opposed by the recessed section of slide guide 62), but the open slide face avoids abrasion of the nonprinted side of the container in slide guide 62. The length of slide guide 63- is greater than that of guide 62 whereby to extend from magazine 56 past magazine 48 for a purpose to be described. The slides 62 and 63 are parallel and on the same vertical level.

Means are provided for simultaneously (1) charging the left-hand side of magazine 48- with a container, (2) discharging a container from the right-hand side of magazine 48 in FIG.'1 through slide guide 62 into the left-hand side of magazine 56 in FIG. 1 and (3) discharging a container from the right-hand side of magazine 56 in FIG. 1 through slide guide 63 onto a receiving apparatus to be described. It is understood that suitable conventional timing and hydraulic actuation means are provided to integrate the operations and steps in the orders specified. These means include three hydraulic cylinders 66, 67 and 68 supported by arms 69, 70 and 71 rela tive to table 20, respectively. A charging slide 72, having a container receiving opening in the top thereof 73 is fed individual containers sequentially by the operator. Charging guide 72 is an elongate hollow box (rectangular in cross section or congruent to the container forms) with open ends adapted to precisely charge containers fed neck down in FIG. 1 therethrough into a cavity 49 in magazine 48 on the left side of the latter in FIG. 1. Cylinder 66 has enlarged cross section plunger 66a of sufficient length to charge a container completely into a cavity 49 of magazine 48 through guide 72. Cylinder 67 has piston 67a with enlarged end thereon adapted to discharge a container from a cavity in magazine 48 through slide guide 62 fully into a cavity 49' in magazine 56. Hydraulic cylinder 68 has a piston 68' of sufficient length (and of reduced cross section because it is hitting the closed bottom end of the container rather than the neck) out of a cavity 49" in magazine 56 completely through slide guide 63 and onto a receiving means to be described. All pistons are actuated simultaneously after a single printing step when both magazines are rotated simultaneously by the movement from left to right in FIG. 3 of the frames 30 and 31.

Means are provided to receive two-side printed containers from slide guide 63 and clear them from the printing area, while preserving the still wet ink thereon in drying relationship. Such means include third rotatable shaft 74 positioned by bearings received in bearing supporting frames 75 and '76 mounted on table 20. Vertical adjustment of the bearings is possible as the horizontal bearing frames '75 and 76 are slot-ted as at 77 (FIG. 2) with bolts carried by vertical mounting means 75a and 75b received in said slots. An hydraulic cylinder 78 driving piston 79 operates through a conventional ratchet 88 connected to shaft 74 and piston 79 to rotate shaft 74 only in one direction, from left to right in FIG. 1 and clockwise in FIG. 2. Ratchet 80 disengages piston 79 from shaft 74 in movement of the piston from left to right in FIG. 1 and engages it therewith in movement from right to left in the same View.

A sprocket wheel '81 is fixedly mounted on the end of shaft 74 opposite ratchet 80 to receive chain 82 thereon carrying a plurality of spikes 83 extending toward table 20. Spikes '86 are of sufficient length to receive containers from slide guide 63 without permitting them to fall by passing into the necks thereof. An elongate frame 84 is fixed to table 20 and includes suitable braces 85 and 86 which carry suitable safety chain guards and guides 87 analogous to the manner of my previous application Serial No. 573,908. A table 86 for the operator to position withdrawn containers thereon is provided attached to frame 84. A platform 89 next to table 88 carries bearings 98 thereon mounting for rotation shaft 91 which itself mounts for rotation a sprocket wheel 92 which engages the other end of endless chain 82.

In operation and considering FIGS. 4-9, the operator places a container 93 in slot 73 of guide 72. Actuated by hydraulic cylinder 66, plunger 66a drives (as shown in dotted lines in FIG. 4), container 93 into cavity 49 of magazine 48. It must be remembered that, simultaneously, two other containers are driven, one printed on one side from the other cavity 49 of magazine 48 and one printed on both sides from a cavity of magazine 56 through slide guides 62 and 63, respectively, for charging into magazine 56 and onto a spoke 83. However, other containers will not be considered in the following description and only the single container 93 will be traced through its entire history in the printing process.

Following charging of container 93 into magazine 48, magazine 48 rotates in a clockwise direction as seen in FIG. 7 and the outwardly facing side of container 93 is printed by squeegee 42 forcing printing ink through screen 33. In this operation, hydraulic cylinder 28 force-s screens 38 and 3 1 from left to right in FIGS. 2 and 3 and, through cable 36, shaft 43 is driven in rotation in the manner previously described.

FIG. 5 finds container 93 with one side printed positioned in front of slide guide 62. Hydraulic cylinder 67 then actuates piston 67w as shown in dotted lines of FIG. 5 to force container 93 through slide guide 63 into cavity 49' of quiescent magazine 56. Following this charging step, the frames, having returned to the left in FIGS. 2 and 3, are again actuated to the right and then returned by cylinder 28 as seen in FIG. 8 with magazine 56 being driven in the same direction of rotation as magazine 48, shaft 43 and shaft 59 rotated by actuation of cable 36 attached to frame 30. Squeegee 41 now prints through screen 32 the other unprinted side of container 93 as shown in FIG. 8. The relieved portion 50' of magazine 56 maintains the already printed side in intact condition.

FIG. 6 finds container 93 after motion according to the arrow of FIG. 6 in the printing step positioned opposite hydranlic cylinder 68. Cylinder 68 is then actuated so that piston 69 drives container 93, as shown in dotted lines, completely through guideway 63 (protected by the relieving 58 and open side thereof as in FIG. 9), onto Waiting spoke 83. Hydraulic cylinder 78 is actuated simultaneously with each actuation of hydraulic cylinder 28 whereby to rotate shaft 74 and sprocket wheel 81 simultaneously with the printing step thus always providing a fresh spoke 81 in front of the discharge and of slide guide 63.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. Apparatus for charging, receiving and discharging a plurality of plastic containers in a process of silk screen printing of a portion of two surfaces of each said container comprising two rotatable magazines having a plurality of spaced cavities extending axially therethrough, each said cavity so formed as to receive and closely confine substantially an entire container, the peripheral portion of each said cavity open to expose an area of a containers to be printed positioned therein, means located opposite one end of a first said magazine to position unprinted containers adjacent said one end of said magazine, a first charging means positioned on the side of said positioning means away from the first magazine but adjacent the same end of said magazine operative to charge a cavity thereof from said positioning means, discharging means positioned adjacent the same end of said first magazine as said first charging means operative to discharge a container from another cavity of said magazine than the one to be charged by said charging means, a first guideway positioned adjacent the other end of said magazine from said first charging means operative to receive a container from a cavity of said magazine opposed to said discharge means, the second magazine so positioned relative to the other end of said first guideway that a cavity thereof may receive a container therefrom, a second discharging means positioned on the other end of said second magazine from said first guideway and operative to discharge a container from another cavity of said second magazine than the one to be charged from said first guideway, and a second guideway positioned on the other end of said second magazine from said second discharge means operative to receive a container discharged from said second magazine by said second discharge means.

2. Apparatus as in claim 1 wherein the first and second guideways are relieved in portions thereof as required to avoid contact with the printing on said container.

3. Apparatus as in claim 1 including a first and a second shaft mounting said first and second magazines, means connecting said first and second shafts for rotation simultaneously together, a frame including two silk screen trays reciprocable back and forth relative to said two magazines, means for reciprocating said frame back and forth, and means coupling said frame with one of said shafts whereby reciprocation of said frames in one direction rotates both of said shafts simultaneously therewith, while reciprocation in the other direction does not rotate said shafts.

4. Apparatus as in claim 1 including movable means for individually receiving and suspending said printed containers discharged into said second guideway by the interior portion thereof upon discharge from said second guideway by said second discharge means.

5. Apparatus as in claim 1 wherein said charging and discharging means each comprise a pneumatic cylinder having a piston rod extendible therefrom and retractable thereinto operable to push a container into or out of one of said magazines.

6. Apparatus as in claim 1 wherein said charging and discharging means are all simultaneously operable.

7. Apparatus as in claim 1 wherein said guideways are positioned in substantially the same horizontal plane and the second guideway is of greater length than said first guideway whereby to extend past said first magazine.

8. Apparatus for charging, receiving and discharging a plurality of plastic containers in a process of silk screen printing of a portion of two surfaces of each said container comprising two rotatable magazines having a plurality of spaced cavities extending axially therethrough, each said cavity so formed as to receive and closely confine substantially an entire container, the peripheral portion of each said cavity open to expose an area of a container to be printed positioned therein, means located opposite one end of a first said magazine to position unprinted containers adjacent one end of said magazine, a first charging means positioned on the side of said positioning means away from the first magazine but adjacent the same end of said magazine operative to charge a cavity thereof from said positioning means, discharging means positioned adjacent the same end of said first magazine as said first charging means operative to discharge a container from another cavity of said magazine than the one to be charged by said charging means, a first guideway positioned adjacent the other end of said magazine from said first charging means operative to receive a container from a cavity of said magazine opposed to said second discharge means, the second mag azine so positioned relative to the other end of said guideway that a cavity thereof may receive a container therefrom.

9. Apparatus as in claim 8 wherein said first guideway is relieved in a portion thereof as required to avoid contact with the printing on said container.

10. Apparatus as in claim 8 including a first and a second shaft mounting said first and second magazines, means connecting said first and second shafts for rotation simultaneously together, a frame including two silk screen trays reciprocable back and forth relative to said two magazines, means for reciprocating said frame back and forth, and means coupling said frame with one of said shafts whereby reciprocation of said frames in one direction rotates both of said shafts simultaneously therewith, while reciprocation in the other direction does not rotate said shafts.

11. Apparatus as in claim 8 wherein said charging and discharging means each comprise a pneumatic cylinder having a piston rod extendible therefrom and retractable thereinto operable to push a container into or out of said magazine.

12. Apparatus for handling a plurality of plastic containers in a process of silk screen printing of a portion of two surfaces of each said container comprising two rotatable magazines having a plurality of spaced cavities extending axially therethrough, each said cavity so formed as to receive and closely confine substantially an entire container, the peripheral portion of each said cavity open to expose an area of a container to be printed positioned therein, first discharging means positioned adjacent one end of a first said magazine operative to discharge a container from a cavity of said magazine, a first guideway positioned adjacent the other end of said magazine from said discharging means operative to receive a container from the cavity of said magazine opposed to said dis charge means, the second magazine so positioned relative to the other end of said first guideway that a cavity thereof may receive a container therefrom, a second discharging means positioned on the other end of said second magazine from said first guideway and operative to discharge a container from another cavity of said second magazine than the one to be charged from said first guideway, and a second guideway positioned on the other end of said second magazine from said second discharge means operative to receive a container discharged from said second magazine by said second discharge means.

13. Apparatus as in claim 12 wherein the first and sec- References Cited in the file of this patent 0nd gu ideways are relieved in portions thereof as required UNITED STATES PATENTS to avoid contact with the printing on said contalner.

14. Apparatus as in claim 12 wherein the mold cavities 1,825,058 f et a1 Sept 1931 of said second magazine are relieved inwardly to avoid 5 2179 6164 Hakogl J1me 1957 contact with printing on said t i 2,866,403 Zlmmerman et a1 Dec. 30, 1958 

